Juicy New Research on Immune Health

New Study Suggests 100% Grape Juice May Play a Role in a Healthy Immune System

CONCORD, Mass., January 14, 2011 - More than a decade's worth of research suggests that drinking Concord grape juice may benefit the heart.1-8 While emerging research has also pointed to Concord grape polyphenols' possible immune health benefits,9-12 for the first time, a study involving humans reinforces that grape juice made with Concord grapes and vitamin C may play a role in supporting adults' immune system health.

To date, the emerging research on Concord grapes and immune health has involved studies using animal and cell models.9-12 This new research by University of Florida scientists, which was published in the January/February 2011 issue of the Journal of Medicinal Food, is the first study with humans and it points to the opportunity for more research on the possible immune health benefits of grape juice made with Concord grapes.13

Grape Juice and Immune Health

The conclusions drawn suggest that daily consumption of 100% grape juice made with Concord grapes and added vitamin C may help support a healthy immune system in healthy adults, though further research is needed. In their study, 85 adults between the ages of 50-75 years consumed either 12 ounces of 100% grape juice or a placebo, grape-flavored drink every day for 9 weeks. Subjects who consumed the 100% grape juice made with Concord grapes showed significantly higher numbers and increased proliferation of a specific type of immune cell, the gamma delta T-cell, compared to the placebo group. (An increase in gamma delta T-cell proliferation indicates an improved ability for these cells to be primed for action and ready to respond to potential invaders.)

The subjects who consumed the 100% grape juice made with Concord grapes and vitamin C also had significantly higher levels of serum vitamin C, which functions as an antioxidant to support a healthy immune system; maintenance of serum antioxidant capacity levels (while the antioxidant capacity of those consuming the placebo drink dropped over the study period); and significantly lower induced DNA strand breaks versus the placebo, suggesting antioxidant protection against oxidative stressors that can damage healthy cells.

It is important to note that in addition to containing polyphenols, each serving of 100% grape juice made with Concord grapes consumed in this study delivered more than 100% of the daily value for vitamin C. The observed positive effects could be the result of the vitamin C, the polyphenols, or both working together. More research is needed before any conclusions can be drawn.

Expert Outlook

According to study author Dr. Susan S. Percival of the University of Florida in Gainesville, "Plant foods contain an array of vitamins, minerals and beneficial plant nutrients (like polyphenols). And, purple plant foods, such as the Concord grape, deliver natural plant nutrients not found in many other colors of fruits and vegetables." She added, "While this study can't directly pinpoint a specific plant-derived nutrient responsible for the positive results seen, it further supports that a healthy diet, rich in colorful fruits and vegetables, like Concord grapes and 100% grape juice, can support a healthy immune system."